NEW YORK (AP) -- The corporate parent of CNN, TNT and TBS on Tuesday offered voluntary buyouts to 600 veteran employees, part of an overall cost-cutting effort at the Atlanta-based broadcasting company founded by Ted Turner.

The offer went out to U.S.-based employees who are over 55 and have worked at the company for at least 10 years, excluding on-air talent and others with specific contracts. Some 9,000 of Turner's 13,000 employees are based in the United States.

The company would not comment Tuesday, saying it should become clear this fall how many employees it will be shedding. Turner Broadcasting chief executive John Martin has been talking for several months about a restructuring plan he has called Turner 2020.

Turner is a division of Time Warner, the media company whose profitability is being closely watched following a spurned takeover bid earlier this year by Rupert Murdoch's News Corp. Turner also owns The Cartoon Network, HLN, Tru TV and Turner Classic Movies.

CNN's chief executive, Jeff Zucker, told some of the news network's employees that "we are going to do less and have to do it with less," according to a partial transcript of a call this week that was quoted by The Atlanta Journal-Constitution.

Zucker has been trying to restructure the news network with a greater emphasis on non-fiction programming that can be aired several times, in addition to ongoing news coverage.

In a letter to employees explaining the buyout offer on Tuesday, Turner management said it was identifying cost savings and shifting spending to high-growth areas.

Although management called the buyout "strictly voluntary," the letter noted that "Turner will also undertake additional reductions in staffing."

TNT and TBS, networks once dominated by reruns of old broadcast shows, are under increased pressure to follow the industry lead and make more original programming.